Module eval_numeric 

Low-level numerical evaluation trait system

This module implements the two-level evaluation architecture following SymPy’s proven design:

1. Low-level EvalNumeric trait: Type-specific numerical evaluation without substitution
2. High-level evaluate() method: User-facing API with substitution, simplification, and control

Architecture

The two-level design separates concerns:

• EvalNumeric::eval_numeric(): Internal trait for numerical conversion (like SymPy’s _eval_evalf())
• Expression::evaluate_with_context(): Public API with substitution and context control (like SymPy’s evalf())

This separation enables:

• Clear semantics for each expression type
• Explicit control over evaluation behavior
• Extensibility for custom types

Mathematical Background

Numerical evaluation converts symbolic expressions to numerical form while preserving mathematical correctness. For example:

• sin(π/2) → 1.0 (exact symbolic evaluation)
• sqrt(2) → 1.4142135623730951 (numerical approximation with precision control)
• x^2 (with x=3) → 9 (after substitution and evaluation)

Structs

EvalContext

Evaluation context

Traits

EvalNumeric